Re: why are anti-human mAb concentrations omitted?

Calman:
We had a similar problem with Serotec two weeks ago - they wouldn't say how
much Ab there is in their DR and CD86 PE, although they did say how much
there is in their FITC ones. Our local representative managed to get higher
up, and it turns out (at least that's what we were told) that they simply
don't check the concentration after conjugation, only before (?!). So their
best answer was "around 0.1 mg/mL", stating 10 micro-L per test =~ 1
micro-g/test. This was after politely implying that we wouldn't be able to
buy any more from them if we cannot know how much Ab we are buying. Maybe 
miltenyi would show a similar change of attitude when faced with a similar 
proposition.
Coincidentaly, when titrated (asumming 0.1 mg/mL, using only 0.2 x10^6
mature DCs) both Abs were very very far from saturation as high
as 3 micro-g/mL, they were actually quite linear up to that point. I dare 
not conclude that it is nefarious, but certainly fishy.

Greetings,
Uriel.



----- Original Message ----- 
From: "Prussin, Calman (NIH/NIAID)" <CPRUSSIN@niaid.nih.gov>
To: cyto-inbox
Sent: Thursday, November 04, 2004 10:06 PM
Subject: why are anti-human mAb concentrations omitted?


> We recently purchased anti-CRTH2 PE  from Miltenyi Biotec (cat#
> 130-091-238,
> clone BM16, rat IgG2a). As has become the custom for many human reagents,
> no
> mAb concentration is given, just the number of tests. Miltenyi does not
> sell
> an isotype control, so I bought a rat IgG2a PE control from a different
> company and then called Miltenyi to get the mAb concentration, which I
> could
> then match for my isotype control. The very personable Miltenyi technical
> service person politely told me that this information is not given out,
> period.
>
> Any suggestions on how to get this information or any other work-arounds?
> This is the first instance when I have called a company and this
> information
> has not been freely given. After paying $375 I find it objectionable that
> Miltenyi is not more forthcoming with the mAb concentration.
>
> I would also like to invite Miltenyi, or any company representative for
> that
> matter, to post the reason/justification for not including mAb
> concentration
> in mass units on their vials or product data sheets. When this information
> is omitted, I presuppose, possibly incorrectly, that the company's
> motivation is nefarious.
>
> Please avoid a discussion of the merits of using isotype controls, as I am
> fully aware of their limitations! Thanks.
>
>> _______________________
>> Calman Prussin
>> Laboratory of Allergic Diseases
>> NIAID/ National Institutes of Health
>>
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